Ripping tool



Fig.4

R. STEWART ET AL Filed April 2, 1924 WITNESS:

RIBPING TOOL 2 Sheets-Sheet 2 2w. wax/m INVENTOR ATTORNEY Patented Dec. 16, 1924.

UNITED STATES RODERICK STEWART AND THOMAS W. WALKER, 0F VERNON, TEXAS.

RIPPIN G TOOL.

Application filed April 2,

To all whom it may concern:

Be it known that we, RODERICK STEWART and THOMAS W. \VALKER, citizens of the United St'ates, residing at Vernon, in the county of Wilbarger and State of Texas, have invented new and useful Improvements in Ripping Tools, of which the following is a specification.

This invention relates to ripping bits for oil well casings, and contemplates a' structure whereby the casing is ripped or cut on the up-stroke of the tool, in contra-distinction to the usual method of cutting the casing on a down stroke, so that the casing can be located from the top of the well and subsequently ripped without injury to the collar or coupling.

Another object of the invention resides in providing a tool of the above mentioned character wherein the cutting elements are associated with automatic operable means which move the elements to a position to permit the tool to be easily and conveniently withdrawn from the well when desired.

The nature and advantages of the invention will be better understood when the following detailed description is read in connection with the accompanying drawings, the invention residing in the construction, combination and arrangement of parts as claimed.

In the drawings forming part of this application, like numerals of reference indicate similar parts in the several views, and wherein:

Figure 1 is a view in elevation of the tool constructed in accordance with the'invention.

Figure 2 is a view taken at a right angle to Figure 1.

Figure 3 is a longitudinal sectional view showing the normal position of the parts.

Figure 4 is a similar View showing the arrangement of the cutting elements while the tool is being withdrawn from the well.

Figure 5 is a detail view of the shoe.

Figure 6 is a detail view of the spring actuated rod operable to'move the blades to an inactive position.

The tool forming the subject matter of the present invention comprising a body portion 10 adapted to be coupled in any suitable manner with a drilling stem and lowered into a well in the ordinary well known manner. The body portion 10 is longitudinally slotted as at 11, the slot opening at one end 1924. Serial N0. 703,713.

of the tool as shown. In fact, the tool is made up of two complementary members of identical construction which are welded or otherwise secured together, the design of the members providing the slot 11 just referred to. The lower end of the tool is equipped with a steel shoe 12 having reduced portions 13 adapted'to be positioned within the slot 11, and riveted or otherwise secured tothe body portion 10 as at 14. Arranged within this slot and immediately adjacent the shoe 12 are cutting blade holders indicated at 15 and pivoted at appropriate points in their length as at 16. Each blade holder is bifurcated at one end as at 17 to accommodate the cutting blade 18. The corresponding ends of these blades are bevelled and formed with projections '19 which normally extend beyond the opposed sides of the body 10 to rip or cut the well c'asing on the up stroke -of the tool. The blades 19 are secured to their respective holders by suitable fastening elements 20 passed through openings in the holders and blades. The adjacent longitudinal edges of these blade holders are curved as at 21 to cooperate with the cam like surfaces 22 formed on the rod 23 at one end thereof, which rod is arranged to slide longitudinally between the blade 8 holders 15. The rod is spring pressed, and is normally held in the position shown in Figure 3, by means of a spring 24 which encircles the reduced extremity 25 of said rod and has one end bearing against a shoulder 26 and its other end bearing against the shoe 12. When the rod. is normally positioned in the manner illustrated in Figure 3, the spring 24 is under tension, and the cutting blades held in their projected positions beyond the sides of the body portion, in which positions they cut or rip the well casing on the upstroke of the too]. To assist the rod 23 in holding the cutting blades in their active positions, we make use of leaf springs 27 which are terminally secured to the opposed sides of the rod 23, and have their corresponding free extremities bearing against the inner longitudin'al edges of the blade holders 15.

For the purpose of holding the rod 23 and the cutting blades normally in the positions described, we make use of a pair of elongated plates 28, the' latter being pivoted within the slot 11 of'the body portion of the tool at opposite sides of the rod 23, the pivots for these plates being indicated at 30. The pivotal movement of these plates are limited by the opposed ends of the elongated slots 31 which are formed in said plates adjacent the free ends thereof, and

receive the stop pins 32 carried by the body portion of the tool. The adjacent longitudinal edges of these .plates are formed with extensions 33 which are designed to normally enga e the enlarged spherical portion 34 formed in the length of the rod 23 thus preventing lon itudinal movement of the rod in one direction under the influence of the spring 24. We also employ a slotted pin. 20' which is passed through the side members 10 and arranged to straddle the rod 23 to hold the latter in a firm position. This pin is clearly shown in Fi ures 3 and 4, and 'f'si'a'rranged upon the ro with relation to the curved-portions 21, sothat these portions will not interfere with the pin when the rod. 23 is released by the spring 24.

In practice, the tool is associated with a drill stem and lowered into the well in the usual manner, and by reason of the arrangement of the parts, the tool is operated on the upstroke thereof, the well casing can be located from the top of the wen, and the tool is lowered until it passesythe'collar or coupling of the casing to be ripped. When the tool is moved upwardly, the cutting edges of the blades 15 rip the casing, so that subsequent to this operation, the sections of the casing can be easily and conveniently re-. moved from its holder or coupling. During the use of the tool, the outer longitudinal edges of the plate 28 bearagain'st theinner periphery of the well casing,which of course prohibits these plates from beingmoved outwardly under'the tensionoif, the spring 24. After the casing has been ripped, the casing is raised a distance sufiicientito remove the plates 28, allowing them to swing outwardly behind the opposed sides of the body portion 10, and thus give freedom of movement to the rod 23, the latter being moved longitudinally of the tool under the influence of the spring 24. During this movement of the rod, the cam like surfaces 22 thereof en age the curved surfaces 21 of the blade holders, rocking -the 'latter on their pivots 16 until the working ends of the.

blades are moved within the slot 11. It will be noted that when the blades are rocked on their ivots 16' in the manner just described, tlie blades are caused to lie flush with the opposite sides of the tool and thus allowthe latter to be withdrawn from the well without any interference, or in other words without the cutting or binding in any other ]0lI1t on the wel casing. One of the advantages of the in= vention over the similar devices which rip the casing on the down stroke is that it is only necessary to rip three to four inches of the casings to release the casin s from the collar and always leaving the co lar in good condition which makes it possible to connect to the collar and easing left in the hole.

While it is believed that from the foreparent, we desire to have it understoo that we do not limit ourselves to-what is herein shown and described, and that such changes may be resorted to when desired as fallwithin the scope of what is claimed.

Having thus described the invention, we claim: v

A tool for ripping well casings comprising a slotted body ortion, a shoe carried by one end of the body portion, opposed cutting elements pivoted within sa1d slot and normally projected beyond the sides of the tool to rip the casin onthe up stroke thereof, a'spring-presse rod arranged to slide between the cutting elements longitudinally of the tool, and designed to move said cutting elements wholly moved in one direct on, means for normally holding the rod inactive against the tension of said spring, said means including plates eld in engagement with said rod by the walls of said well casing, and adapted to be moved away from said rod under the tension of said spring to effect a release of said rod, when said plates are separated from the casg- In testimony whereof we aflix our signatures.

RODERICK STEWART. THOMAS W. WALKER.

blades catchin ivoted within said slot and adapted to be within the slot when I l 

